<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    .box {
      width: 500px;
      height: 700px;
      border: 1px solid green;
      display: flex;
      /* flex-wrap: wrap; */
      /* flex-flow: column wrap; */
      /* align-items: baseline; */
      align-content: space-around;

      /* justify-content: flex-start; */
      /* flex-wrap: wrap; */
      /* flex-direction: row-reverse;  */ /* 反转8*/
      /* flex-direction: column-reverse; 反转8 */
    }
    .laoda {
      width: 100px;
      height: 100px;
      background: red;
      margin: 10px;
    }
    .child {
      height: 100px;
      background: rgb(110, 103, 103);
      border: 1px solid blue;
      flex-basis: 32.93%;
    }
  </style>
  <body>
    <div class="box">
      <div class="child">1老一</div>
      <div class="child">1老二</div>
      <div class="child">1老三</div>

      <div class="child" style="align-self: center">2老一</div>
      <div class="child">2老二</div>
      <div class="child">2老三</div>

      <div class="child">3老一</div>
      <div class="child">3老二</div>
      <div class="child">3老三</div>
    </div>
    <div></div>
  </body>
</html>
